Sealed expansible mandrels

ABSTRACT

Expansible mandrels are disclosed that have means operable to force the sections into a pile-gripping relationship and to draw them together to effect their pile-entering relationship. The mandrels are provided with resilient means sealing the abutting side and boot edges of the sections so that when the sections are spaced apart, the ingress of dirt and mud through the resulting gaps between said edges is prevented.

United States Patent 1191 Guild et al.

' 1111 3,802,207 Apr. 9, 1974 SEALED EXPANSIBLE MANDRELS Inventors: Charles L. Guild, Stone Towers Ln.,

Barrington, R.I. 02806; Willard B. Goodman, PO. Box 62, Newport, Oreg. 97365 Filed: Sept. 8, 1972 Appl. No.5 287,534

US. Cl. 61/53.72

Int. Cl E0211 7/30 Field of Search..... 61/53.72; 242/72; 2 79/2 References Cited UNITED STATES PATENTS 777,351 12/1904 Raymond 61/5372 700,707 5/1902 Raymond 6l/53.72

Primary Examine'r-Jacob Shapiro [5 7 ABSTRACT Expansible mandrels are disclosed that have means operable to force the sections into a pile-gripping relationship and to draw them together to effect their pileentering relationship. The mandrels are provided with resilient means sealing the abutting side and boot I edges of the sections so that when the sections are spaced apart, the ingress of dirt and mud through the resulting gaps between said edges is prevented.

12 Claims, 12 Drawing Figures PATENTEDAPR 919M (802,207

' sum 2 0F 2 SEALED EXPANSIBLE MANDRELS BACKGROUND OF THE INVENTION The present invention relates to expansible mandrels for use in driving or withdrawing tubular piles and the like.

In order that a tubular pile can be driven into the ground, it must be secured to a mandrel that can absorb the hammer energy that would damage a tubular pile under usual conditions if such energy were applied directly thereto. Expansible mandrels have been provided with various means for forcing their sections apart from a contracted, pile-entering relationship into an expanded, pile-gripping relationship.

A typical expansible mandrel has two arcuate sections, each less than 180 in extent so that its chord length is less than the diameter of the pile to be driven. The mandrel sections thus may have a first relationship in which their side edges and the edges of their boots at their pile-entering ends abut and in that position the mandrel is a free fit within the pile. When the mandrel is within the pile and its sections forced apart, each section engages and grips a substantial portion of the pile but with substantial gaps then existing between the edges of the sections and their boots.

In all expansible mandrels, a troublesome problem has been that when the sections are in their pilegripping relationship, dirt can and does enter through such gaps.

THE PRESENT INVENTION The objective of the present invention is to provide expansible mandrels that have their sections, including the boots at their earth-entering ends, so sealed that dirt and mud cannot enter into the interior of the mandrel while piles are being driven.

This objective is attained by the use of resilient seals between the edges of the boots and between the edges of the mandrel sections that are drawn together to enable the mandrel to be inserted into a pile and that define substantial gaps when the sections are forced apart into their pile-gripping relationship. The seals are so disposed that they cannot be damaged when the mandrel sections grip the pile and form no part of and in no way interfere with the means by which the mandrel sections are moved into or out of their pile-gripping relationships.

In one embodiment of the invention, a mandrel is protected by seals, each in the form of a strip of spring steel and anchored to the surface of one gap-defining margin to overlie and resiliently and slidably engage the adjacent surfaces of the other gap-defining margin as the mandrel sections are forced apart or drawn together.

In other embodiments of the invention, the seals are of elastomeric materials thus to be compressible as well as resilient and are held between the edges of the gapdefining margins of the arcuate sections and their boots to be compressed when the mandrel, thus protected, is readied for insertion into a tubular pile and to expand to the required extent as its sections are forced apart into their pile-gripping relationship.

In one such elastomeric type, each seal includes a tubular portion which may be secured to but one edge of each two gap-defining margins while in another type, two elastomeric strips are employed for each seal, one

for the edge of each gap-defining margin and secured thereto.

In all embodiments of the invention, the seals must lie within the circles their arcuate sections define. See US. Pat. No. 967,879, and in any mandrel in accordance with the invention, different combinations of seals may be used.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings, there are shown illustrative embodiments of the invention from which these and other of its objectives, novel features, and advantages will be apparent.

In the drawings:

FIG. 1 is a partly sectional, somewhat schematic view of a mandrel taken lengthwise of its sections;

FIG. 2 is a fragmentary, lengthwise section of the head end of the mandrel on an increase in scale, taken with the mandrel turned from its FIG. 1 position;

FIG. 3 is a section of the boot or lower end of the mandrel taken approximately along the indicated line 3-3 of FIG. 1;

FIG. 4 is a cross sectional view of a mandrel section on an increase in scale, .taken substantially along the indicated line 44 of FIG. 1;

FIG. 5 is a section taken approximately along the indicated line 55 of FIG. 1;

FIG. 6 is a view of the bottom or boot end of the mandrel with the sections in their pile-gripping relationship;

FIG. 7 is a fragmentary section taken substantially along the indicated line 77 of FIG. 6;

FIG. 8 is a section taken approximately along the indicated line 88 of FIG. 1;

FIG. 9 is a boot end view of a mandrel provided with a seal in accordance with another embodiment of the invention with the sections in their pile-gripping relationship and partly broken away to show the sealing of the gap between one pair of their side edges;

FIG. 10 is a like view but with the mandrel sections in their pile-entering relationship;

FIG. 1 1 is a view, similar to FIG. 9, illustrating a mandrel seal in accordance with yet another embodiment of the invention; and

FIG. 12 is a like view but with the mandrel sections in their pile-entering relationship.

THE PREFERRED EMBODIMENTS OF THE INVENTION Mandrels in accordance with the invention are not limited as to the type of means employed to force their sections apart into their pile-gripping relationship and to draw them together to effect their relationship in which they are a free fit within a pile. The invention is illustrated, however, with such operating means of a type shown in our co-pending US. Pat. application Ser. No. 151,786, filed June 10, 1971 as that type of operating means has proved to be successful in all respects and also illustrates the desirability of sealing the mandrel against the ingress of dirt and mud into its interior. For that reason, the general construction of the mandrel and its operating means is detailed before describing the different sealing means shown in the drawings.

In FIG. 1, an expansible mandrel is shown that has a pair of arcuate sections 15, each of substantial length and of an arcuate extent less than 180 so that when the sections are closed together, the mandrel may be entered into a tubular pile of a particular diameter and tightly grip that pile when the mandrel sections are forced apart to a predetermined maximum extent. The mandrel sections are preferably provided with ribs to effect positive gripping engagement with the interior of the entered pile, but these are not shown as they form no part of the present invention.

It will be noted that each mandrel section 15 includes marginal portions 15A corresponding ones of which abut when the mandrel sections are in their pileentering relationship and that these portions having outer flat surfaces 158 that lie in the same plane and are within the circle with the mandrel sections define when they are in their pile-gripping relationship, see FIGS. 3 and 5, 9 and 10, and 11 and 12. This construction is desirable in order that the arcuate mandrel sections closely approach the diameter of that circle.

The sections 15 are connected at their upper ends to a drive head, generally indicated at 16 and shown as having an outwardly disposed flange 17. The upper end of each section 15 has an external reinforcement 18 and also has an end plate 19 welded thereto providing an outwardly disposed flange portion 20 securely clamped to the head flange 17 by means of bolts 21 which also secure an interposed, inwardly tapered shim or wedge sections 22. The thus attached ends of the mandrel sections 15 are spaced apart but the shims 22 bias them inwardly towards each other a short distance below the head.

The attached end plates 19 define an axial passageway 23, see FIG. 2, with a concave seat 24 receiving a spherical washer 25. A bolt 26 extends freely downwardly through the passageway 23 and has a locked nut 27 on its upper end seated against the washer 25. Links 28 are connected by a pivot 29 to the other end of the bolt 26 and by a pivot 30 to the hanger 31 of a fluid pressure operated ram 32 with the hanger 31 extending at one side between the mandrel sections 15 thereby to prevent the supported ram 32 from turning.

The stem 33 of the ram 32 has a fork 34 to which a hanger 35 is secured by a pivot 36. Links 37 are connected to the hanger 35 by a pivot 38, disposed at right angles to the pivot 36 and rotatably support a sprocket 39. A chain 40 is trained about the sprocket 39 and' each end thereof is attached to the appropriate one of a pair of yokes 41, each rotatably supporting a doublegrooved sheave 42.

The other ends of the mandrel sections 15 are closed by boots 43 and, see FIG. 3, one has an intermediate end member 44 welded thereto and including a key portion 45 slidably entrant of a keyway 46 in an intermediate member 47 welded to the other mandrel section to prevent misalignment of the boot ends of the section 15 as they are moved between their pileentering and their pile gripping relationships. It will be noted, see FIG. 6, that the boots are of the same size and shape as the arc and chord defined by each mandrel section.

To effect the pile-gripping relationship of the mandrel sections, operating means are provided that include a pairof cables 48 and a plurality of sheaves 49 and 50 arranged in groups with the sheaves 49 and 50 alternately disposed in each group, the sheaves 49 connected to one mandrel section 15 and the sheaves 50 connected to the other mandrel section. The cables 48 are in trained engagement with the sheaves 49 and S0 in a manner subsequently described. The number of sheaves in each group may vary as may the distance between them with the number of sheaves in a group decreasing and the spacing between the groups increasing towards the head to ensure the maximum pile-gripping force is applied in the lower portion of the mandrel as the resistance of the earth to its penetration increases with its depth.

Each mandrel section 15 has internal reinforcements extending lengthwise thereof throughout most of the length of the mandrel, In the zones of the sheave groups, reinforcements 5 1 of a right angular section are welded in positions to define a central channel C for the sheaves and the cables and while they may extend as far along the sections as reinforcement is needed, the reinforcements between the groups are shown as plates 52, each with its margins welded to the edges of a mandrel section. The reinforcements 51 of each section have transversely aligned pairs of bars defining seats 53.

Each of the sheaves 49 and 50 has four grooves and is rotatably supported in a U-shaped mount 54 shaped and dimensioned for slidable entry into an appropriate one of the seats 53 and to bear against the mandrel section that forms the bottom of that seat with each sheave dimensioned to extend into the opposite channel C with clearance between it and the bottom thereof when the mandrel sections are in their pile-entering relationship. The mounts 54 have guide rollers 55, see FIG. 8, arranged to hold the cable courses in the appropriate sheave channels.

The key portion 45 has a pair of substantially axial anchors 56 and between the uppermost group of sheaves and the sheaves 42 that is connected to the ram 32, there is a four-groove guide sheave 57 and a twogroove fixed sheave 58. The cables 48 have both of their ends connected to the anchors 56 and both courses of both cables are trained in the same manner about the sheaves of the several groups in succession. It will be seen that the cable courses are sinuous as alternately they pass part way around a sheave 49 and then part way around a sheave 50 with the engaged portion of each sheave being that which is within the channel C of the section 15 to which it is not attached so that a pull on the cables tends to straighten them and, in so doing, forces the mandrel sections 15 into their pilegripping relationship. Each course of both cables 48 engages an appropriate groove of the guide sheave S7 and is trained about an appropriate one of the ram sheaves 42 and has a single turn about the fixed sheave 58.

The mandrel sections 15 are yieldably urged into their pile-entering relationship by pairs of resilient connections generally indicated at 59, one pair interconnecting the members 44 and 47 and other pairs spaced at suitable intervals lengthwise of the mandrel to ensure the return of the sections into their pile-entering relationship to enable the mandrel to be withdrawn when the ram 32 is relieved of operating pressures. With the exception of the pair of connections interconnecting the members 44 and 47, the connections of each pair are longitudinally spaced and on opposite sides of the channels C. As shown in FIG. 5, the mandrel sections 15 have sockets 60 with corresponding sockets of the two sections 15 transversely aligned and with a bolt 61 extending from one to the other. In the sockets of each connection 59, the bolt 61 has locked retainers 62 each confining a compression spring 63 against the bottom of each socket which thus yieldably urge the two sections together.

From the foregoing it will be apparent that an expansible mandrel of the type described, while of a construction well adapted to meet all demands, must have the mechanism by which its sections are forced apart protected against dirt and mud.

To that end, the margins A of the mandrel sections adjacent their gap-defining edges are protected by seals 64, each in the form of a strip of spring steel extending from the boot end of the mandrel towards its head, desirably to the reinforcements 18 with one edge welded to the flat surface 158 of one mandrel section to overlie the flat surface 15B of the other mandrel section with its other edge inturned as at 65. Desirably each seal 64 is welded to the same mandrel section. In the pileentering relationship of the mandrel sections, the free, seal edge 65 extends sufficiently beyond the flat surface 158 of said other mandrel section to engage the arcuate surface thereof, see FIG. 5. As the mandrel sections 15 are forced apart into their pile-gripping relationship, the seal edges 65 are brought into sliding, resilient engagement with the flat surfaces 15B of said other mandrel sections and maintain the gap between the edges of the mandrel sections tightly sealed, see FIG. 3.

The boots 43 are shown as having recessed margins 66 extending along their abutting edges. A seal 67, also in the form of a length of spring steel, is welded to the margins 66 of one boot 43 and is dimensioned to overlie the margin 66 of the other boot with its free edge inturned as at 68 thus to have resilient, sliding engagement with underlying margin 66 to ensure a tight seal at the boot end of the mandrel as its sections are forced apart into their pile-gripping relationship.

In FIGS. 9 and 10, the margins 69A of both mandrel sections 69, are like the mandrel sections 15, provided with outer flat surfaces 69B lying in the same plane when they border the abutting edges thereof. In this embodiment of the invention, each edge of each margin 69A has a seal 70 in the form of a strip of elastomeric material secured thereto and desirably extending lengthwise of the mandrel to the same extent as the seal 67. As shown, the seals 70 expand from their compressed state, see FIG. 10, to maintain the gaps between the sections 69 resiliently sealed when the sections are in their pile-gripping relationship, see FIG. 9. It will be noted that the seals 70 extend into the mandrel and are secured to the co-planar portions of the internal reinforcements of the mandrel sections of which the right angular reinforcements 71 are shown in FIGS. 9 and 10. Similar seals 72 are secured to the gapdefining edges of the boots 73.

In the embodiments of the invention illustrated by FIGS. 11 and 12, the mandrel sections 74 are shown as similar to those previously described in that each has internal reinforcements 75 portions of which are in the plane of its edges and with the outer surfaces 74B of its marginal portions 74A flat so that those at each side of the mandrel are in the same plane.

The longitudinal seals 76 are tubular extrusions having vents 77 opening into the interior of the mandrel. Each seal 76 is formed with a base 78 secured to an edge of a mandrel section 74 and the co-planar portion of the reinforcement 75 adjacent thereto to enable the seal 76 to be dimensioned to resiliently engage the opposite gap-defining edge and reinforcement of the other mandrel section 74 when they are in their pilegripping relationship and not protrude outwardly too far when the mandrel sections 74 are drawn together. Like seals 79 are provided to seal the gap between the gap defining edge of the boots 80, the base 81 of the seal 79 being secured to one such edge.

It will thus be apparent that the invention makes possible the effective sealing of an expansible mandrel with resilient seals that do not interfere with the operating means and can be readily serviced without dismantling the mandrel. While in each embodiment, the side and boot seals are always shown as of the same type, a mandrel may have any type as its boot seal and any other type as its side seal.

We claim:

1. An expansible mandrel for use in driving or withdrawing tubular piles, and the like, said mandrel comprising arcuate sections, a head connected to and joining the upper ends of the sections, and means operable to vary the spacing of the sections between pileentering and pile-gripping relationships, said sections each being less than in extent and, in a pilegripping relationship, being positioned approximately to define major portions of a circle, said sections including marginal portions and inwardly disposed boot portions at the pile-entering ends of the sections, corresponding ones of said portions abutting in said pileentering relationship but otherwise being separated to provide gaps, and said mandrel also including resilient and compressible sealing means, one for each lengthwise gap and closing it in any relationship of said sections, each sealing means connected to at least one of the mandrel sections and being within said circle, and resilient means for the gap between .the boot portions and closing that gap in any relationship of said sections and connected to at least one of the boot portions.

2. The expansible mandrel of claim 1 in which at least one of the sealing meansclosing each lengthwise gap is a strip of spring steel welded to one marginal portion defining that gap and in sliding resilient engagement with the other marginal portion defining that gap.

3. The expansible mandrel of claim 1 in which the outer surfaces of the marginal portions bordering each lengthwise gap are flat and lie in the same plane and the sealing means closing each lengthwise gap is a strip of spring steel one margin of which is welded to one marginal portion defining that gap and its other margin includes an inwardly disposed bend in sliding engagement with the other marginal portion defining that gap.

4. The expansible mandrel of claim 3 in which each strip of spring steel is of such width that, in the pileentering relationship of the mandrel sections, it lays against said other gap-defining margin with its inwardly disposed bend extending beyond it.

5. The expansible mandrel of claim 1 in which at least the sealing means closing the gap between the boot portions is a strip of spring steel welded to one of them and in sliding resilient engagement with the other marginal portion defining that gap.

6. The expansible mandrel of claim 5 in which the free margin of the spring steel strip includes an inwardly disposed lengthwise bend.

7. The expansible mandrel of claim 1 in which the outer surfaces of the boot portions are flat and lie in the same plane and the sealing means closing the gap between the boot portion is within that plane.

8. The expansible mandrel of claim 1 in which at least the sealing means closing one gap is of a resilient and compressible elastomeric material and is confined between the edges of the margindefining that gap.

9. The expansible mandrel of claim 8 in which the sealing means is an extrusion including a tubular portion and a base secured to one of said edges, the cross sectional size and shape of said tubular portion being such that it is in resilient engagement with the other of said edges in the pile-gripping relationship of the mandrel sections, and the tubular portion has inwardly disposed vents.

10. The expansible mandrel-of claim 8 in which the sealing means comprises two lengthwise strips, one for each of said edges and secured thereto, the combined thickness of the two strips being such that they are in resilient engagement with each other in the pilegripping relationship of the mandrel sections.

11. The expansible mandrel of claim 8 in which the mandrel sections have internal reinforcements in the plane of their edges and the sealing means extend inwardly in engagement therewith.

12. The expansible mandrel of claim 1 in which the resilient means for the gap between the boot portions is also compressible. 

1. An expansible mandrel for use in driving or withdrawing tubular piles and the like, said mandrel comprising arcuate sections, a head connected to and joining the upper ends of the sections, and means operable to vary the spacing of the sections between pile-entering and pile-gripping relationships, said sections each being less than 180* in extent and, in a pilegripping relationship, being positioned approximately to define major portions of a circle, said sections including marginal portions and inwardly disposed boot portions at the pile-entering ends of the sections, corresponding ones of said portions abutting in said pile-entering relationship but otherwise being separated to provide gaps, and said mandrel also including resilient and compressible sealing means, one for each lengthwise gap and closing it in any relationship of said sections, each sealing means connected to at least one of the mandrel sections and being within said circle, and resilient means for the gap between the boot portions and closing that gap in any relationship of said sections and connected to at least one of the boot portions.
 2. The expansible mandrel of claim 1 in which at least one of the sealing means closing each lengthwise gap is a strip of spring steel welded to one marginal portion defining that gap and in sliding resilient engagement with the other marginal portion defining that gap.
 3. The expansible mandrel of claim 1 in which the outer surfaces of the marginal portions bordering each lengthwise gap are flat and lie in the same plane and the sealing means closing each lengthwise gap is a strip of spring steel one margin of which is welded to one margiNal portion defining that gap and its other margin includes an inwardly disposed bend in sliding engagement with the other marginal portion defining that gap.
 4. The expansible mandrel of claim 3 in which each strip of spring steel is of such width that, in the pile-entering relationship of the mandrel sections, it lays against said other gap-defining margin with its inwardly disposed bend extending beyond it.
 5. The expansible mandrel of claim 1 in which at least the sealing means closing the gap between the boot portions is a strip of spring steel welded to one of them and in sliding resilient engagement with the other marginal portion defining that gap.
 6. The expansible mandrel of claim 5 in which the free margin of the spring steel strip includes an inwardly disposed lengthwise bend.
 7. The expansible mandrel of claim 1 in which the outer surfaces of the boot portions are flat and lie in the same plane and the sealing means closing the gap between the boot portion is within that plane.
 8. The expansible mandrel of claim 1 in which at least the sealing means closing one gap is of a resilient and compressible elastomeric material and is confined between the edges of the margin defining that gap.
 9. The expansible mandrel of claim 8 in which the sealing means is an extrusion including a tubular portion and a base secured to one of said edges, the cross sectional size and shape of said tubular portion being such that it is in resilient engagement with the other of said edges in the pile-gripping relationship of the mandrel sections, and the tubular portion has inwardly disposed vents.
 10. The expansible mandrel of claim 8 in which the sealing means comprises two lengthwise strips, one for each of said edges and secured thereto, the combined thickness of the two strips being such that they are in resilient engagement with each other in the pile-gripping relationship of the mandrel sections.
 11. The expansible mandrel of claim 8 in which the mandrel sections have internal reinforcements in the plane of their edges and the sealing means extend inwardly in engagement therewith.
 12. The expansible mandrel of claim 1 in which the resilient means for the gap between the boot portions is also compressible. 